Touch sensors and proximity sensors have a myriad of uses. For example, they can function as buttons, sliders, or switches for user interface. These sensors can be found, for example, on kiosks, handheld electronic devices, and home appliances. They can be operated by pressing with a finger, touching a screen with a stylus, or even by the mere presence of a body as a proximity sensor.
The sensors themselves act as a capacitor. As the sensor is pressed, or as a body approaches it, the capacitance qualities of the sensor are changed. By determining the value of the capacitance or comparing it to known or previous quantities, information such as whether a contact was made or for how long contact was made can be determined.
Capacitive sensors are popular alternatives to mechanical buttons and switches, particularly, in microcontroller or microprocessor applications. Consequently, engineers seek to implement them more cheaply with fewer components. Systems and methods for easily measuring and detecting changes in capacitance, while simplifying designs and reducing the requisite number of components are desirable.